DAMAGE ZONES IN STRAIN-HARDENING MATERIALS

In this paper, damage distribution and damage zones of a strain harden ing material with a crack are investigated. A continuum damage mechani cs theory based formulation is developed via the hypothesis of increme ntal complementary energy equivalence. Damage distributions in the reg ion of the crack tip are calculated and the results are compared with those computed using the finite element method. Very good agreement is observed, particularly at high strain hardening exponents. Next, the sizes of damage zones along a crack are formulated based on the Dugdal e model with damage. The results are checked against the solutions fro m a finite element analysis. Again, very good agreement is observed. I t would also be interesting to compute the Dugdale plastic zone which is obtained by extending the Dugdale model for elastic-perfectly plast ic materials to strain hardening materials. It is found that the Dugda le plastic zone is comparatively larger than the damage zone predicted by our proposed model but as the strain hardening exponent is increas ed, the two results agree much better.